Testing apparatus for the measurement of the internal physical properties of solids



Oct. 2l, 1952 A. KEPES 2,614,415

TEsTING APPARATUS PoR THE MEASUREMENT oP yTHE INTERNAL PHYSICAL PROPERTIES 0E soLIns Filed Dec. l, 1949 4 Sheets-Sheet 1 I: i l. 47 Z /7 W K j. f E :l

ff M n 54 @ENA gw-f4 rl' 57M f4 E l J ,I/ Fv V 0 E v JNVENToR.

Oct. 21, 1952 A. KEPEs 2,614,415

TESTING APPARATUS RoR THE MEASUREMENT oF THE INTERNAL PHYSICAL PROPERTIES oP SoLIDs Filed Dec. 1. 1949 4 sheets-sheet 2 Y v Y 3 'rmlllllll V INVENToR.

Oct. 2l, 1952 A. KEPES 2,614,415

TESTING APPARATUS FOR THE MEASUREMENT OF THE INTERNAL PHYSICAL PROPERTIES oF somos Filed Deo. l, 1949 4 Sheets-Sheet I5 IN VEN TOR.

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Oct. 2l, 1952 'A KEPES 2,614,415

TESTING APPARATUSEOR THE MEASUREMENT OF THE INTERNAL PHYSICAL PROPERTIES OF SOLIDS Filed Deo. 1, 1949 4 Sheets-Sheet 4 I: i Y. W

e ('/0 *E--- o fof*r frequencies vwhich Patented oci. 21;; 1952 fg( asTATEs in'r- Nr ERICE i -TESTINGLAPPARATUS Fon 'rms'ME-As,URE-

fMENrpE THEl INTERNAL PHYSIGAL `Eno,Plnrrnss-or" SOLI-Ds An'drrlyepes, Saint"-Mande,"France, assignor to Societe-Anonymedes Manufactures d'esGlases F. -,."&.Cireyf, Paris-France nve'ntion'relatesl to'an :apparatus for -fmodulusliof'feiasncityior'suhfsoiius.

v1923"; `lt/lagon conceived the `nica-of "measur- Aing thev coeflicient of jinternal :friction Ao'f` a'rod by rotatng'it Withone' end deflected bylateral ftensiongtliecomposite; dele'cton, 4of the end of "the piece byte'nsionand rotationfb'eingftakenas the jmeas'ure o'lthe coemcient 'The practice off that theory j has: never i beenfsatisfactory bbc.. Ncause `of a -multitude "of" A'difficulties- Which' introduced errors'fofgreat':magnitude"and even of jprinciple. For example; fthisinve'ntion has dem'onstrated"that 'the coeflciient fk is not indep'enentsof the= freque ciesV 'but varies `as a "func tion-either `'aref'varc'rle fromo'ne material to' another, which reque'n'cy'and according'v to laws which lis'y contrary .tof the" former theory." I

" Itiisfariobject 'of-tlii's( 4invention to test the `physical properties' of'soli'dsvfsirnply', quickly, and

accurately,l and to 'extend the tests 1' i'nto ranges '-"lavefnot' heretofore" been *"Ano'ther vObject ofA vthe invention is to Vfcon 'structf'an 'apparatus #capable-'OP testing' physical propertiesl'ofi solidsa'ccuratelm VSrfli and 'fth'rough'o'ut ranges' 'of Afrequencies" noti' heretofore iavlilble with' prior apparatus.'

"1 f Another' obj ect Aof 'the invention is to 'measure 'thedefletion of test1piecesfmore'vacciirately.

:Another object "or fthe 'invention-is to"l con- -lstructffapparatu's ":capable'r :lof "recording fthe' defle'otionfofitest pieces' .more accurately @and ithrough lfa* Ainrit-ler rangethan' vhas i heretofore been possible; `'lInthereduction. of the yconcepts 'of 'the Ainventionptoipractice dependent.:inventions` were'imade ln order to overcome variou'st problems' `which .h'adinot :been solved i bythe prior art' I and Vwhich fre'qnired '1 isolutionfiifm I kthe maj or :invention lwas f tot be* completely rsuccessful.

inventions-i will 'befr described `elsewhere .in 'the ,fspecication 1 y 'In ;the--acc.o'mpanying drawings there isset :f kortl'ixia;y representation of `a'ppre'ferrecl lform of the `novel:apparatus l f 'Figure/,h-is :an elevational view-of the `:exte- ;rior" ofthefapparatus. n. y

. 'iFg. I 2 is 4'a vertical-:sectional viewthrough .the s'apparatus which operates upon the test piece..

fJ5i g.i.3 a diagrammatic perspectiveyiew of the apparatus ysfhichV measures the `deilection and jthefphysical; properties, of Ythe/test piece.y

Eig-.fa lisva side .view-of .the apparatus Shown inEg- 3." A y 'These dependent 7 'ola-img. (01573-100)- Y' "testin he I'Jhys'ical' properties `of `rsolids particu- "fet P'r'oduifSChimiques de Saint'- Gobain; Chauny v2 f -rig. 5 isadetair'df'tne gripping and driving 'constructionsof the vapparatus:-

Fig; 6 is ci-'perspective feet-'ailier Enie wpAv if `wheel 651 diagrammatically llustrates"mea`nsffor rotating the'test piece inside'thef'tbular frame I I by m'eans'of ain-appropriate drive;l concealed after;

llte'ferri'ng'-nOWi'to Fig". 2*, the-l base I0 ksupports Athe tubular frame" II byme'ansfof afsm'allflange, ly'vliich rests'upon' the ,ba's'e'l0`,' andfaxset'sscretv I El'I r Whi'chioperates 'on' a'V camprin'ciple, fsecuring the? flanget'ghtly against the Lface "and the'fframe rmly [in place. At' the'ftop'foff the frame ISI", an annular groove I5 isprovide'd; havinga :right section,.and in that vgrooveismountellfan anti- Africtionl bearing""I5.F This *bearing Ais itself'A at- 'tached by screws `20- to-cap 'ring I 'I-Which isvin turni'a'ttached tozframe II by 'screws 20', The

`Acap yring Il Ahas'a ange- I8; iwhich` engages fthe top fof bearing il and .an internal landV I @which l*bears upon :a 'cooperatingland-of theV bearing. Thef tubular frame II carries at-its lower-end a removable bearing support I2- which -isxheld on :the :framenII by screws :I2-I located-conveniently. A tubular bearing-fstud--I-'is mounted in the' support I2 'and/projects upwardly. be-

yondfithe support, ser-ving` ais-a supporting... core for the ball-1 bearing-I4 and `'as-,a portieri-,the

i 'admission 'Lof ziluids;` such Ar as:- air of ,selected'ltemthe bearing I4, is provided with a groove 22 in,v

which a drive belt 23 is trained and imparts rotation to the cylinder 24 from any selected source' l of power. A cylinder 24 is mounted on the block 2|, in this instance by screw threads, and has at its upper end a bearing 25 which engages the circular bearing |6. Bearings |4, I6 and '25 are,

of course, coaxial so that-the rotatable cylinderv 24 is coaxial with the frame and can beoper ated therein at any selected speed.

In order to carry out the purposes of the invention, a test piece is mounted in this rotatable cylinder 24. The mechanism by which the test piece is mounted in the rotatable cylinder 24 forms part of the invention and permits `the alignment of the test piece upon a true axis so that it also is coaxial with the frame I cylinder 24, and bearings I4 and 25 during operation.

The test piece itself is preferably a carefully machined Arod 43 which is true to its axis. As shown in the drawing, it has a reduced end 44 which is held in a vise-like grip by the split end of sleeve 32, whichris of comparatively thin and solid construction at its top and of massive con- -struction at its base, having slots 34 extending radially `upward fora distance sufficient to lend flexibility to the sections between the slots, and

lhaving a center bore of approximately the same diameter as the reduced end 44 of the test piece 43. f f, t

vThe externalwall lof the split sleeve 32 has a conical shoulder 33 oppositerthe gripping portions of the` sleeve for the purpose of applying gripping action by the sections to the end of the test piece.

Mounted in the screw threaded bore of end block 2| is a screw threaded ring 3B which has an internal cone which bears upon the conical .shoulder 33 in the split sleeve so that the sleeve may be made to grip the test piece by turning the screw threaded ring 38, applying camming action against the grippingy sections through the engaged faces of the cones.

Mounted upon the screw threaded upper en -of the split sleeve 32 is a lug nut 36 which bears against a terminal shoulder in the solid end of sleeve 32 and has projecting lugs 31 whichenter into driving sockets 39 in the screw threaded ring 38. The lugs t the slot accurately in a circumferential direction but permit relative motion in an axial direction so that driving contact between the lug nut 36 andthe cam ring 38 is maintained in various positions of the cam ring.

Also mounted upon the screw threaded end of split sleeve 32 is the adjustable test sample support 29 which is screw threaded on the sleeve 32 in tight locking engagement with the lug nut 36. By rotating the adjustable testr sample support `29, the lug nut 36 screws the ring 38 against the v 29 downward so that the ilange 4|), which projects outwardly from the top of the support 29, is brought into firm engagement with a spherical face 21 on the top of bearing 25. The flange 49 vis provided with an annular edge 4| which en gages theI spherical surface and xes the suD- port 29 upon the rotating cylinder 24 so that in Visra'ccurately set atv a selected height upon the upper end of th'etest piece 43 by means of Wedges 45, and it has'at its end a projecting pin 41 which is cylindrical and serves as a bearing for a tiny ball bearing v50.

Even the most careful mounting of the cap 46 and of' the testpece 43 may still leave an imperfection in the centering of the pin 41 on the axis of rotation of cylinder l24, so an adjustment is provided whereby the axis of the pin may be perfectly aligned upon the axis of the cylinder.

A screw 28 is mounted in the cap ring |1 and bears upon the side of ilange 40. In centering the pin 41, thehand wheel 65 is rotated slowly and a reading is taken, by the apparatus hereafter described, to see iffthe pinis centered.-` If it shows a deflection, the screwr 28 is used to move the flange v4E!- of support 29 slightly over the vspherical surface 21. Further rotation of the cylinder 24 may disclose otheraberrations, which arein-turn corrected bythe .screw 2B until furtherrotation showsnodeflection throughr a full turn ofthe cylinderr29. Alignment having thus been secured, theapparatus isfready for the test.

In the cap piece |1 are vsome holes |1 which may receive post 5 as shown in Figures 3, 4 and 2, having radial arms 52 with opposed bearings for pivot pin 53. t The length oithe arms'brings the pivots in posts 53into alignment with the axis of thecylinder hereinbefore referred to. A bar 55 p-rojects laterally from the pivot pin 53, to which it is affixed, and supports the frame 54 on horizontal .pivots 55. in. projecting ears 54?. By this construction, the frame 54 is given universal movement, turning horizontally With rod 53 and vertically about bar 55. A lug 6| projects horizontally from the frame 54 and is provided with a Vertical aperture and a bearing which, receives the pin 41 of the cap 46. above the bearing 5D. A spring 51. is welded at its lower` end to the rod 53 and bears against roller; 56 which is mounted on ay rod 56 whichf-is pivoted at its ends in the frame 54 as shown in Figure 9. Attached to the spring 51is amirror 58 upon which a beam of light Yis directed fromA the sourceA 60, the beam being reected to a graph- 59. When tension is applied by cord 63 to bearing 50 and pin 41 the test piece is deflected in the direction of the pull, and when the cylinder is'rotated the test piece is rotated andcauses a `lateral orr circumferential deflection.

The mathematical principles upon which the apparatus works are explained in connection with Fig. 7. In this gure, O represents the position of the axis of pin 41 when no force is ap'- plied to it. O is the new position of this point when the force F is applied to it (by vcord 63) without rotation of the test piece. When the test piece is rotated counterclockwise around'its axis the force F conserves the same direction but'the rot-ation moves the axis of the pin "from the position O" to O2.` The speed of rotation being maintained constant the pin Will nd a position of equilibrium 'tat O2. The force? applied at O2 may be divided into its components f' and f2. The component f"=F sin :p works to return the point O2 to O" and thus works against the forces" of internal friction. As O2 is a position of equilibfcoe'fcient, 10 of "the test r piece holder fby-f means. of a slotted Thus one can write: sleeve which can be clamped'V upon: iii-,..the "lampf 1 f ingfaction' -beingfo'btained by meansffofisaniiterf('.j1'.) J=f-f23kv f i nally conical nut which'acts-'uponl 'an fext'ernl t cone'upon the sectors of thetest piece support. 15 In a modificationjofA the invention, the cap piece 156 is omitted and the test piece 43 is formed Y at its end with a bearing-pin, comparable to pin vbeirrg'xa certa-nf-Cnstanih 41,npfimwhichfthebearingktlllrides andftq which 'ThuS thef'stress `ofythe. cord .is applied?, l, l fl ...Sina I i f :zu .I-n-,fcar-ryingiout theinventiontheapparatusis (Ztnw: dismantled, leaving only? theV tubrrlarr' trame 5ft! I 0, I v:mounted-on the base i,.1andfthef1 :2fl?f#Salis i 'heOIYFS'IOWSz thaUK=21f @Ddlthlls -TZ" @afnfpl vfrnounted .by-.wedges'c onthefcylinder test piece ."FOT Smalljanges one may asslmllatetheiange whichisrdescribedfor purposesjofi'llustratinn withitsftangent and thus one mayassume lloto 25-35 'beilgimade` of, Yinyndng.chloridf.;` qghemut be 21f 'is--screwed dow n' fon,-tqthesplit^sleevef-3f2--.as Itws therefore seen that inpracticemhe'meas' far -as it -willgo,'-.as,-showninFigurezZ andrthe ure Aof the` coeicient of internal friction klsre- "tesi-Sample supportiscrewed` dowgonfiqp'mf ducvedto a measurementof the an g1f fit. MvThe, testpiecef'llfisinow mounted'bylitsrend 'AS'O the C0mP011ent-f2=F 00S felt-15151115 force 30.44111 ,thespiit baseof .thesieeveffsz,.mariages Which-111190595 011 the test P1603' the aTTOW sbeing inplace; but-tof.-coursenotiexercising:cam-

OO2=e permitting ronelto measure the modulus Hmmgvracton on theonenfithegsmibasewlgow, .of ,elasticity E" by thfi formula: the assembled testpiece and-.,:testmiece support t Lspcosvj .are` inserted in the top@ of 1t-hes cylinderrdauntil (2) 'E= 'W frm the screw 38 engagesy thte- Athreads .fof yend v .the y'arrow -e=`OUO2 in. accordance with 'formulafz In `thisfformulaI is the momentof inertiao'f the-section .of .the test. piece around an; axis, .sit-

" uated, in itsplane andv L. is thelengthfffthetest 4* piece..l

threads. y into :thetubular frame I-'l -until;theyenclfblockgisu `.seate'di uponsthe .-roller bearing- I-4rf'an'd hthe'fupper vas the-'lower'bearing for the. cylinder lmayizhe-.a ball bearing ;r the upperfpartof-the ntest'gsample support is provided-.Withmeans `for,:. 'ali'gnment f susceptible of Y being 1 moved spherically-ffwithire- @spect .to'th'e'- said'. machined vb'earing anda.'

which the center iszfttted at'.the` baseofithe'itestsamplersupport. so'asrtopermit' alignment ofthefen'd "off the ltestlv piecefcapfbyf radiali 'displacemenmzthe flower: part of the test; piece fis seizedin'fthefbase fblock. -2| ands a few' turns are` igivenftossetfgthe The rotatable` cylinder :2li -fis tirent-@slid iso; perfectly machined that lubrication fisfiun-` I grd necessary.y v A yfewuiturns yfon @theay iendibleclc. 2 I serres-to set the filange tilxfanid. clampthertest in the vcase ofnne cylindrical testipiece tjr-which dis the diameter. j

'Thus vknowing .the vforceil andl the anglev ip. the modulus of elasticity isgiv'enby measuring the arrow. e=OO2 in` accordance with Formula12'..

It is therefore seenthat.in.practice the'mea's- `ure `of""the coefficient of internal-'friction is.re duce'd'to a measurement of theangleq:r and`,.'f`u.r

the modulus of. elasticity isigiven'r by measuring `'terrnaerature otherthan atlat-nro'spheri'du .gasfof the .requisite temperaturenlis f blown'ithrougli-holj the, arrow 2: 002 in accordance.with'Forinulafil f"The 'following principles rare.characteristicfof 'i this invention. "gThetest piece, vertically aligned. is'. mounted in a 4tubular Yshaft .byk attachment Lof y 1theidesireclftemperature;y

The i* test piece having been properly centered,

the mirror is mounted on the tubular `frafme|l turning the apparatus and observing t light not" properly centered, Abut aminorfadjustment -corrects this yso that Ythe lightdaes not `lwat/er "In a preferred form-of the invention theap- 'fparatus presents the' following features;l therotation ofthe rotating cylinder or tubularsha'ftzis `'carriedv outin bearings of .which two are"tte`d.in

@the upper partofythe apparatus andare ma- *on* the chartas4v the shaft isturned'this Jconsti- 'sion,for instance cf' 25Q`1grams iszpapifiliedy little '.by littleto its endr so*v that the. lightzspotisslowly displaced. rAfter Several'Y seconds,I rthe'"'to`t`aly tension having been applied, Zit assumesaggpositin y chined Ywith such'precision that they turn l' With y Y the .coordinate .o'fj whichls. noted', Lier-example, A*respect to' each'other-'withoutlubrication,"where- 75 76 mm. vertically and`5'5 mmiliorizontally. "The accurate results. "at constant speed have been successfully comoperation-is repeated for decreasing speeds for example, 350, 100, 35, 10, 5, 3', and 1 R. P. M. and

atv each speed the coordinates corresponding to the position ofthe point of light are noted on the graph.` From the horizontal coordinate, the

angle theta is immediately deduced which permits one to obtain the Vcoefficient k of internal friction;L FromV the vertical coordinate, one derives, the arrow e which permits the calculation v,of the modulus of elasticity of the test piece by .the formula hereinabove given where no cap is employed on the test piece, and by the formula 'thatfollows when a cap 'is used;

Eample .At C. a perfect cylinder of polyvinylidene chloride was prepared andmounted as shown 4in'ligure 3 anda 2,50 gram weight was loaded atm62; a brake being applied to the pulley B4 so that no tension reached the pin on the end of ther cap. lThe test piece was then rotated'at 1000 R. P. M. and the weight was released progresfsively until full tension was applied to the cap pin. After several seconds, the beam of-light i fixed itself on the graph a reading was taken,

f say a function of the frequency of the vibrations imposed on the test piece.

Many rother tests have been carried out with different materials quickly, and with extremely Tests by variation of weight plete'd.

The apparatus can be employed to determine :the coefficient of friction between two solids con- *stituted by different materials. For this purpose, the ball bearing 50 is replaced by a cylinder ring of the rst material which is made to lrotate with the cap. This apparatus being in rotation, one may bring progressively toward this ring, a test piece of the second material.

The said ring tends, at the moment of contact, to roll, without sliding, on this test piece and to occupy a position of equilibrium atwhich relative sliding motion commences and which is afunction of the coefficient of friction between the Ytwo solids. vThis displacement is registered as in 'the other cases by the mirror of the measuring unit. The angles through which the 'mirror hasvturned is a function of the coefcient of friction.

^The new method and apparatus can also be yapplied to the measurement of the coeicient of friction between two objects madeof the same v material or two objects made of different materials.y

Thegprinciple employed in the invention is of lcontinuous rotation and not the pendulum movement employed in certain prior art concepts. The vertical position of the test piece is a feature of some importance, as it eliminates errors Y found in prior art attempts to employvthe earlier and more primitive principle of Mason. The construction ofthe novel apparatus permits the centering of the test piece precisely on the axis of the apparatus, thus eliminating another series `of imperfections, particularly to those sorts `which arise from the influence of gravity.

- The principle of multiplying the movements or deflections of the test pieces'makes it possible to use comparatively small deiiections .and to eliminate the use of long-test pieces which might not be homogeneous in all their parts and which would consequently have errors arising from the lack of homogeneity.v

The measurement of the coeiiicient of internal friction and of the modulus of elasticity is made simultaneously by the simple observation of a luminous spot.

As many apparently widely different embodiments of the present invention may be made without departing from the spirit and scope thereon, it is to be understood that the invention is not limited to the specic embodiments.

I claim:

l. Testing apparatus including a vertical frame, a cylinder rotatably supported in said frame and having an upper face, a testing rod holder connected at the lower end to said cylinder and having universally adjustable engagement with 'said face, a cap constructed and arranged to grip a test rod held by the holder,

land bearing means for connecting tensioning apparatus to said cap.

2. Testing apparatus including a vertical frame, a bearing supported by the lower end of the frame, a-coaxial bearing supported by the upper end of the frame, a coaxial cylinder rotatably supported by said bearings and having an upper spherical face, driving means for rotating said cylinder, a test piece holder held at the lower end by said cylinder and having universally adjustable contact with said spherical face, a tubular cap constructed and arranged to grip a test piece held by said test piece holder, tension means connected to said cap to warp the test piece, and movably mounted measuring means operatively connected to the cap for dedection by said cap during rotation of the test piece under tension.

3. Testing apparatus including a base, a vertical frame secured to the base, a bearing removably supported by the lower end of the frame, a coaxial bearing supported by the upperY end of the frame, a coaxial cylinder rotatably supported vby said bearings and havingan upper spherical face, an internally screw threaded end block 'engaging the` lower bearing and provided with 'driving means, an internally conical nut engaged with the screw threads of the end block, a sleeve split at one end .to form a grip for a test rod, threaded at the other end and having an external cone about the split engaged with the conek of' the said nut, a cylinder having an end mounted on said sleeve and a flange at the other end movable into xedcontact with the said spherical face and driving means connecting the end block and the cylinder. l

4. Testing apparatus including a base, a vertical frame secured to the base, a bearing removably supported by the lower end of the frame, a coaxial bearing supported by the upper end of the frame, a coaxial cylinder rotatably supported by said bearings and having an upper spherical face, an internally screw threaded end block engaging the lower bearing and provided with driving means, an internally conical nut engaged with the screw threads of the end block, a sleeve split at one end to form a grip for a test rod, threaded at the other endand having an external cone about the split engaged with the cone ofV the said nut, a cylinder having an end mounted on said sleeve and a ange at the other tical frame secured tothe base, a bearing removably supported by the lower end of the frame, a coaxial bearing supported by the upper end'of the frame, a coaxial cylinderrotatably supported by'said bearing and having an upper spherical y face, an internally screw threadedfend block engaging the lower bearing and provided with driving means, an internally conical nut engaged with the screw threads of the end block and I having sockets in the upper part, a sleeve split shaped at one end toform a grip for a'test rod, threaded at the other end, and having an external cone, about the split end, engaged with the cone of the said nut, a lug nut mounted on the threaded end of the said sleeve having driving lugs engaged with said sockets, a cylinder having an end screw threaded on said sleeve and a flange, at the other end, movable into xed contact with the said spherical face, an adjusting screw mounted on Nsaid frame and bearing on the said flange, aftubular cap constructed and arranged to grip the test rod, tension means connected to the 4pin and aligned to Warp the test rod, a mirror universally mounted onthe frame and constructed Aand arranged to be moved by said cap, a light source trained on said mirror, and a graph receiving the beam reflected from said mirror.

[6K-Testing apparatus including a base, a vertical tubular frame secured to the base, a bearing support removably attached to the lowerl end of. the frame, an annular stud extending through the support coaxially of the tubular frame, a

a' bearing about the stud, a coaxialbearing `supported by the upper end of the tubular frame, a coaxial cylinder, rotatably supported by said stud bearing, engaged by said upper bearing, and provided with a spherical face, an internal screw threaded end block engaging the lower bearing and provided with driving means, an

internally conical nut engaged with the screw threads of the end block and having sockets in the upper part, a sleeve split 'at one end and threaded at the other end, adapted to grip one end of a test rod and having an external cone about the split end engaged with the cone of the nut, a lug nut mounted on the threaded end of the said sleeve having driving lugs engaged with said sockets, a cylinder having an end screw threaded on said sleeve and a flange, atthe other end, held in xed contact with the said spherical face, an adjusting screw mounted on said frame and bearing on the said flange, a tubular cap seated on the test rod and provided with a projecting pin, a bearing about said pin, tension means connected to the bearing on the-,pin and aligned to warp the test rod, a post mounted on the said tubular frame, a mirror universally mounted on the post and constructed and arranged to be moved by said pin, a light source trained on said mirror, and a graph receiving the beam reflected from said mirror.

7. Testing apparatus including a vertical frame, a cylinder rotatably supported in said frame and having an upper face, a testing rod holder con-V nected at the lower end to said cylinder and having univerally adjustable engagement with said face, and tension means including a collar adapted to apply lateral tension to a test rod mounted in said holder.

ANDR KEPES. f

REFERENCES CITED The following references are of record in the 

